1. Field of the Invention
The present invention relates to a printing method of printer apparatus.
2. Description of the Related Art
In conventional printer apparatus, in the case where a sheet feeder jam has occurred, either of the following two methods has been adopted.
(1) The printer apparatus was stopped at once, and the occurrence of a sheet feeder jam was presented at an operator's panel etc. Then, the operator was asked to relieve the jam. After the operator had relieved the sheet feeder jam, the printing process was re-started. In this case, the medium in the course of printing was abandoned.
(2) Although, in principle, it is the same as (1); in the case where there was a sheet already printed on one of its faces at the moment of occurrence of the sheet feeder jam, the printing process was continued on the other face. After this medium was issued, the printing process was stopped, and the occurrence of the sheet feeder jam was presented at an operator's panel etc, so as to request relief of the jam. After the operator relieved the jam, the printing process was re-started. Here, the sheet feeder jam means a state where a sheet feeding sensor does not become turned ON, despite passing of a certain time interval from the start of a sheet feeding operation.
However, the following problem remained unsolved in the conventional art mentioned above. That is, at the moment of occurrence of a sheet feeder jam, the case where a sheet exists waiting in the duplex printing unit printed completely on one of its faces. In this case, the printing process was stopped as well. Then, the operator had to exclude the sheet waiting in the duplex printing unit as well as the operator having to relieve the sheet feeder jam. Otherwise, the printing process could not be re-started.
As a result, when the printing process was re-started, it had to be done about the part which is the same as the part already completed printing on one face. Further, when a sheet feeder jam occurred, even if the printer was in the state that sheet feeding from another sheet feeder or duplex printing unit was possible: the printing process was stopped at once as well.